The overall objectives of this research are to understand the physiology of bacterial conjugation by continuing our exploration of the events proceeding in the donor and in the zygote. In the donor, events leading to conjugation appear to be determined by the sex factor; hence, genetic and enzymatic analysis of this episome are together one of the main activities to be continued. In the zygote, recombination and repliconation are the two major processes of inheritance; hence, genetic and enzymatic analyses of these processes will also be continued. We can use the recovery of recombinant and plasmid-carrying bacteria and recombinant viruses as clues to the activities of the various genes in vivo. In vitro activities of potential gene products will be detected with purified forms of nucleic acids. BIBLIOGRAPHIC REFERENCES: Miller, Robert V. and Clark, Alvin J.: Purification and properties of deoxyribonucleases of Pseudomonas aeruginosa. J. Bacteriol. 127, 794-802, 1976. Guyer, Mark S. and Clark, Alvin J.: cis-dominant, transfer-deficient mutants of the Escherichia coli K-12 F sex factor. J. Bacteriol. 125, 233-247, 1976.